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Biomedical subjects

B Dong

Publications and source records attributed to B Dong.

At least 19 recordsLinked to original sources
PubMed2007

Optimizing typhoid fever case definitions by combining serological tests in a large population study in Hechi City, China.

Blood culture-based diagnosis can only detect a fraction of the total burden of Salmonella enterica subsp. enterica serovar Typhi. The objective of the study was to detect additional typhoid fever cases through serological tests. A total of 1732 prolonged fever episodes were evaluated using three serological tests, Widal, Tubex and Typhidot-M in a typhoid fever endemic area of southern China. A case definition which included a positive Widal test (TO>or=80 & TH>A), a positive Tubex test (>or=4) and a positive Typhidot-M test, increased the detection of cases by more than twofold from 13 to 28 cases. The case definition has a specificity of 100% and a sensitivity of 39%. Case definitions based on combinations of serological tests can detect additional typhoid fever cases with higher specificity than a single serological test. Improved case detection is essential to understand the true disease burden and can help to boost the power of intervention trials.

Adolescent↗
PubMed2006

Overexpression of phosphatase of regenerating liver-3 in breast cancer: association with a poor clinical outcome.

BACKGROUND: Increasing evidence has suggested that phosphatase of regenerating liver-3 (PRL-3) plays an important role in cancer cell migration, invasion and metastasis. However, the correlation between the PRL-3 expression and clinical outcome in breast cancer has not been investigated. PATIENTS AND METHODS: Using a PRL-3-specific monoclonal antibody 3B6, PRL-3 expression was assessed by immunohistochemistry in tumor tissues from 382 breast cancer patients with a median follow-up of 65 months. RESULTS: We found that 34.8% patients expressed a high level of PRL-3 protein in their tumors. Patients with a high level of PRL-3 in the tumor had a worse disease-specific survival (DSS) rate than those with a low level of PRL-3 (74.0% versus 84.9%, P = 0.011), and PRL-3 remained an independent prognostic marker for DSS (HR 1.8, 95% CI 1.1-2.9, P = 0.019) in multivariate analysis. More importantly, in 219 node-negative patients, PRL-3 showed a significant correlation with DSS in univariate analysis (P = 0.014) and retained a borderline significance (HR 2.65, 95% CI 0.92-7.64, P = 0.071) in multivariate analysis. CONCLUSIONS: Our results suggest that PRL-3 may serve as an unfavorable prognostic marker in breast cancer, especially for patients with node-negative diseases. Thus, our findings may provide useful information for individualized therapy in the clinical setting.

Adult↗
PubMed2006

Thrombolytic therapy for pulmonary embolism.

BACKGROUND: Thrombolytic therapy is usually reserved for patients with clinically serious or massive pulmonary embolism (PE). Evidence suggests that thrombolytic agents may dissolve blood clot more rapidly than heparin and might reduce the death rate associated with PE. However, there are still concerns about the possible risk of adverse effects of thrombolytic therapy, such as major or minor haemorrhages. OBJECTIVES: To assess the effectiveness and safety of thrombolytic therapy in patients with acute PE. SEARCH STRATEGY: We sought trials through the Cochrane Peripheral Vascular Diseases Group's Specialised Register (January 18, 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2006), MEDLINE (January 1966 to December 2004), EMBASE, CINAHL, LILACS and SCISEARCH (all November 2004). We also searched individual trial collections and private databases, along with bibliographies of relevant articles. Relevant medical journals were handsearched. The most recent search was on February 6, 2006. SELECTION CRITERIA: Randomised controlled trials that compared thrombolytic therapy with placebo or heparin or surgical intervention in patients with acute PE. We did not include trials comparing two different thrombolytic agents or different doses of the same thrombolytic drug. DATA COLLECTION AND ANALYSIS: Two authors (DB and WQ) assessed the eligibility and quality of trials and extracted data. MAIN RESULTS: Results were similar between thrombolytics compared with heparin alone or placebo and heparin in terms of:a) death rate: odds ratio (OR) 0.89; 95% confidence interval (CI) 0.45 to 1.78; b) recurrence of pulmonary embolism: OR 0.63; 95% CI 0.33 to 1.20;c) major haemorrhagic events: OR 1.61; 95% CI 0.91 to 2.86;d) minor haemorrhagic events: OR 1.98; 95% CI 0.68 to 5.75. We found no trials comparing thrombolytic therapy to surgical intervention. Using recombinant tissue-type plasminogen activator (rt-PA) and heparin together compared to heparin alone appeared to reduce the need for further treatment for in-hospital events (OR 0.35; 95% CI 0.17 to 0.71). Thrombolytics improved haemodynamic outcomes, perfusion lung scanning, pulmonary angiogram assessment and echocardiograms to a greater extent than heparin alone. AUTHORS' CONCLUSIONS: We cannot conclude whether thrombolytic therapy is better than heparin for pulmonary embolism based on the limited evidence found. More double-blind RCTs, with subgroup analysis of patients presenting with haemodynamically stable acute pulmonary embolism compared to those patients with a haemodynamic unstable condition, are required.

Fibrinolytic Agents↗
PubMed2005

Compensatory caspase activation in MPP+-induced cell death in dopaminergic neurons.

Many have hypothesized that cell death in Parkinson's disease is via apoptosis and, specifically, by the mitochondrial-mediated apoptotic pathway. We tested this hypothesis using a mouse dopaminergic cell line of mesencephalic origin, MN9D, challenged with the Parkinsonism-causing neurotoxin MPP+ (1-methyl-4-phenylpyridinium ion). Apoptosis was the main mode of cell death when the cells were subjected to MPP+ treatment under serum-free conditions for 24 h. Caspase-3 and caspase-9, however, were not activated, thus indicating the existence of alternate or compensatory cell death pathway(s) in dopaminergic neuronal cells. Using caspase inhibitors, we demonstrated that these pathways involve caspase-2, -8, -6 and -7. A time-course study indicated that activation of caspase-2 and -8 occurred upstream of caspase-6 and caspase-7. Upon MPP+ challenge, the apoptosis-inducing factor was translocated from the mitochondria into the MN9D cytosol and nucleus. These results suggest the existence of alternative apoptotic pathways in dopaminergic neurons.

1-Methyl-4-phenylpyridinium↗
PubMed2005

Cloning and expression of bovine sodium/glucose cotransporter SGLT2.

The second member of the Na(+)/glucose cotransporter family, SGLT2, is a low-affinity active glucose transporter. In humans, it is predominantly located on the apical membrane of the S1 and S2 segments of renal proximal convoluted tubules, and, thus, may be mainly responsible for the reabsorption of D-glucose from the glomerular filtrate. By BLAST searching the GenBank database, we found expressed sequence tag sequences of SGLT2 in the cDNA library of bovine mammary tissues, indicating its expression in bovine mammary gland. To facilitate study of the mechanism of glucose reabsorption in bovine kidneys in maintenance of glucose homeostasis of lactating cows and the potential role of SGLT2 in the mammary gland, we cloned bovine SGLT2 and examined the distribution of its mRNA expression in bovine tissues. The full length mRNA of bSGLT2 is 2275 bp, and is predicted to encode a protein of 673 amino acids, with a molecular weight of approximately 73 kDa. The deduced amino acid sequence of bovine SGLT2 is 91, 90, 91, and 90% identical to human, rabbit, mouse, and rat SGLT2, respectively, and is 58 and 48% identical to bovine SGLT1 and SGLT5, respectively. The sequence of bSGLT2 contains several characteristically conserved sodium:solute symporter family signatures. Analysis of current bovine genomic data indicates that the bovine SGLT2 gene may consist of 14 exons. The major in vitro transcription and translation product of bovine SGLT2 cDNA migrated at an apparent molecular weight of 55 kDa. The SGLT2 mRNA was detected predominantly in bovine kidney as a 2.3-kb transcript, and at lower levels in all other bovine tissues examined, including the mammary gland, liver, lung, spleen, intestine, and skeletal muscle, as a 3.0-kb transcript. Expression of SGLT2 mRNA in bovine mammary gland increased more than 10-fold from late pregnancy to early lactation, similar to SGLT1. This indicates that SGLT2 may play a role in milk synthesis in the lactating mammary gland.

Amino Acid Sequence↗
PubMed2004

Comparison between standard Goldmann applanation prism and disposable applanation prism in tonometry.

BACKGROUND: Disposable devices are increasingly becoming the preferred choice where possible in contact medical equipment. AIM: To evaluate the accuracy of the disposable applanation tonometer head as a potential substitute to the standard Goldmann applanation head. METHODS: The study was prospective. The intraocular pressure recordings in 80 eyes of 42 patients were compared using the disposable and standard Goldmann applanator heads. The Bland and Altman method of assessing agreement between two methods of clinical measurement was used in the analysis. RESULTS: The difference in the readings between the two types of tonometer heads was highly variable (mean difference=0.78 mm Hg, range=-1 to 11 mm Hg). This was because of the distortions on the applanating surface of the disposable device. When the readings associated with the defective heads were excluded, very strong agreement was obtained (mean=0.07 mm Hg, range=-1 to 2 mm Hg). CONCLUSION: Good agreement with standard Goldmann applanation is achieved with the disposable heads except where surface distortions induce significant errors. Careful inspection to ensure well-structured disposable units is imperative in disposable applanation tonometry.

Adult↗
PubMed2003

Driving ability after pupillary dilatation.

BACKGROUND: The Royal College of Ophthalmologists' guidelines and Driver and Vehicle Licensing Agency (DVLA) recommend that a patient should not drive with dilated pupils based on the rationale that vision may be compromised in acuity and ability to tolerate glare. Arguments exist against these recommendations suggesting that pupillary dilatation does not have any real bearings on driving ability. Aim To determine the effects of pupillary dilatation on the ability to drive. METHODS: The study was randomised and prospective. A total of 28 patients had their visual parameters (distance vision, near vision, licence plate reading at 20 m or shorter, and glare) measured and analysed pre- and post-tropicamide 1% dilatation. Paired two-tailed Student's t-test and chi(2)-test were used in the analysis. RESULTS: At 20 min, following instillation of one drop of tropicamide 1% there is a significant reduction in visual acuity (VA), for distance Snellen and near. There is a significant reduction in the number of people who could read the licence plate at 20 m. Subjective glare assessment changed from 'none' (average score) in the undilated state to 'mild' in the dilated states. The overall patient feedback indicated that a significant 14% believed they would find it difficult to drive postdilatation. CONCLUSION: This study demonstrates the rationale behind disallowing driving following pupillary dilatation. The risks to safe driving are proved significant as a result of significant reduction in visual quality and quantity after dilatation.

Adult↗
PubMed2002

Effects of aluminum on physiological metabolism and antioxidant system of wheat (Triticum aestivum L.).

The Al-tolerant cultivar TAM202 and the Al-sensitive cultivar TAM 105 of winter wheat (Triticum aestivum L.) were exposed to 0, 50, 75, 100 or 150 microM of Al. The absorption of Al by wheat, the growth of root, several key enzymes concerned with C, N and P metabolism, as well as key constituents of antioxidant system, were investigated. The results showed that TAM105 absorbed more Al than TAM202 and its root growth (presented by the length) was inhibited more severely. The root growth was most closely related to mononuclear Al (Ala) activity. The metabolic enzymes (presented by glucose-6-phosphate dehydrogenase, nitrate reductase and acid phosphatase) in TAM202 were Al-tolerant. Presented by superoxide dimutase (SOD) and the content of reduced glutathione (GSH) and malondialdehyde (MDA), antioxidant system in TAM202 indicated lower oxidative stress and greater ability to protect the cultivar.

Absorption↗
PubMed2001

Self-assembled monolayers of new dendron-thiols: manipulation of the patterned surface and wetting properties.

SAMs based on a novel dendron-thiol system, which maintain the alkanethiols' active site, but with the -SH group connected to independently variable groups by a dendron-linker, showed a controllable surface pattern and wetting properties. The precisely tailored structure of dendron-thiols with locally controlled hydrophobic and hydrophilic peripheries allows the formation of designed surface structures on a gold surface, e.g. nano-stripes, honeycomb and homogeneous structures.

Journal Article↗
PubMed2001

[Functional assessment of infiltrating immunocytes in patients with primary hepatocellular carcinoma after percutaneous microwave coagulation therapy].

OBJECTIVE: To assess the function local immune cells in patients with primary hepatocellular carcinoma (HCC) after percutaneous microwave coagulation therapy (PMCT). METHODS: Thirty-eight patients with histologically proved primary HCC underwent ultrasound guided PMCT. Specimens were taken from the lesion site before and 17 days after PMCT respectively using 18-guage core needle through US-guide biopsy, embedded in paraffin, and stained by immunohistochemistry. The panel of monoclonal antibodies of CD3, CD56, CD68 and Fas-L were used to detect the CD3+, CD56+, CD68+ cells and T lymphocyte Fas-ligand. The positive cells were detected under light microscopy. Their diameter and area and the Fas-L expression rate of T lymphocytes and changes of secondary lysosomes in macrophages were measured by computer. RESULTS: Before PMCT, only a few infiltrating immunocytes were seen in the tumor specimens; the diameter of most CD3+ and CD56+ cells was less than 10 microns and the diameter of CD68+ cells was less than 18 microns. The amount and volume of CD3+, CD56+, and CD68+ cells significantly increased after PMCT (t = 3.48, P = 0.025 for CD3+ cells, t = -4.76, P = 0.000 for CD56+ cells, and t = -2.46, P = 0.028 for CD68+ cells). The percentage of CD3+ and CD56+ cells with the largest diameter > 10 microns increased from 10.4% and 20.1% respectively before PMCT to 24.9% and 30.2% respectively after PMCT. The percentage of CD68+ cells with the largest diameter > 18 microns increased from 10.2% before PMCT to 33.4% after PMCT. The Fas-l expression rate of T lymphocytes increased from 7.2% to 20.1% (t = -19.12, P = 0.000). The secondary lysosomes and cellular debris within microphages and the cellular organs in T lymphocytes significantly increased. CONCLUSION: The function of intratumaral infiltrating immunocytes is significantly enhanced after PMCT.

Adult↗
PubMed2001

Monitoring activation of ribonuclease L by 2',5'-oligoadenylates using purified recombinant enzyme and intact malignant glioma cells.

A wide range of methods have been developed to study RNase L activation in cell-free systems and in intact cells. Many of the original methods were developed in the laboratory of I. Kerr in the early 1980s (e.g., see Knight et al.). Additional methods described in this article were developed or adapted from research in other fields after the cloning of RNase L and the appreciation of its role in apoptosis. These methods provide the basic techniques needed to induce RNase L activation in vitro and to measure some of its biological effects in living mammalian cells.

Adenine Nucleotides↗
PubMed2001

Basis for regulated RNA cleavage by functional analysis of RNase L and Ire1p.

RNase L and Ire1p are members of a superfamily of regulated endoribonucleases that play essential roles in mediating diverse types of cellular stress responses. 2'-5' oligoadenylates, produced in response to interferon treatment and viral double-stranded RNA, are necessary to activate RNase L. In contrast, unfolded proteins in the endoplasmic reticulum activate Ire1p, a transmembrane serine/threonine kinase and endoribonuclease. To probe their similarities and differences, molecular properties of wild-type and mutant forms of human RNase L and yeast Ire1p were compared. Surprisingly, RNase L and Ire1p showed mutually exclusive RNA substrate specificity and partially overlapping but not identical requirements for phylogenetically conserved amino acid residues in their nuclease domains. A functional model for RNase L was generated based on the comparative analysis with Ire1p that assigns novel roles for ankyrin repeats and kinase-like domains.

Amino Acid Sequence↗
PubMed2001

Computer-aided dynamic simulation of microwave-induced thermal distribution in coagulation of liver cancer.

To develop a method of dynamic three-dimensional (3-D) simulation of thermal distribution in ultrasound-guided microwave coagulation therapy of liver cancer and to verify its accuracy. The specific absorption rate (SAR) values were established by measuring the temperature in equivalent phantom tests. Those values were different under different power output condition. Dynamic 3-D temperature distributions were reconstructed with a finite-element model. Testing and rectification were performed through animal experiments and clinical trials, respectively. The temperature curves in the experiments corresponded well with simulated ones in vitro--91.4% and 88.9% using single and double electrodes, respectively. The measured coagulated boundary and simulated temperature boundary had a good correspondence in 85.7% of the specimens. In both in vivo experiments and clinical trials, blood perfusion influenced the rise in temperature significantly. Temperature curves between the simulations and actual measured results showed good correspondence--67.8% (19/28) in the patients with hepatocellular carcinoma. Distance between electrodes and combined thermal distributions were both optimized with computer-aided simulation during simultaneous two-electrode coagulation. The results demonstrated that computer-aided simulation of microwave thermal distribution is an accurate and reliable method which provides a theoretical and technical basis for controlling coagulated tissue volume and placement of the electrodes during microwave coagulation therapy of liver cancer.

Animals↗
PubMed2001

[Ultrafiltration of micropolluted water in combination with coagulation and PAC process].

The experiments of ultrafiltration of Huangpu River water with coagulation and powered activated carbon (PAC) combinations was evaluated. The results showed that coagulation and PAC pretreatment effectively remove dissolved organic matters (DOM), of which coagulation removes high molecular weight (MW) DOM and PAC removes low MW DOM. Coagulation and PAC are effective treatment for removing Trihalomethane Formation Potential (THMFP). In terms of low MW THMEP, coagulation removes poorly and PAC removes effectively. The results also showed that addition of coagulant and PAC reduce cake resistance greatly. At coagulant dosage 4 mg/L (as Al), cake resistance was minimized.

Charcoal↗
PubMed2001

[Aluminum toxicity and tolerance in wheat].

The physiological and biochemical effects of different species of aluminum on the wheat Al-tolerant TAM202 and Al-sensitive TAM105 were investigated. The results showed that mononuclear Al could be absorbed by both of the two strains. Compared with TAM105, however, TAM202 absorbed less aluminum. The pH of the nutrient solution rose with the hydroponics of the two-cultivars. The content of proline in leaves of TAM105 increased obviously. The contents of protein, hexose and uronic acid in cell wall of TAM202 were higher than that in TAM105 under 75 mumol.L-1 Al. The results indicated that Al can activated the synthesis of some components relative to Al-tolerance in cell wall.

Aluminum↗
PubMed2001

[Social economical status, behaviors and environment as the risk factors of tuberculosis in Chengdu China].

OBJECTIVE: To study the risk factors of pulmonary tuberculosis in Chengdu, Southwest China. METHODS: A population-based case-control study was used which included 174 cases selected from 12 communities in Chengdu and 174 controls selected from registered population with normal chest radiograph. Cases were active TB patients which were matched for age, sex with controls, then interviewed by trained interviewers using a standardized questionnaire. RESULTS: Social economic status measured by education, occupation and income did not show obvions influence to TB; It found that the active smoking, passive smoking, type of cigarettes and alcohol consumption had no significanct effects on TB during logistic regression analysis. The study showed that a person who was smoking and also alcohol intake had a higher risk to get TB (OR = 6.12, 95% CI = 1.15 - 32.49). Significant association was showed in the Dose-Response Analysis (OR = 1.37, 95% CI = 1.30 - 2.30). Crowded living space (OR = 1.14, 95% CI = 1.05 - 1.25), degree of darkness (OR = 2.18, 95% CI = 1.11 - 4.27) and moisture (OR = 4.06, 95% CI = 2.25 - 7.33), poor sanitary (OR = 3.03, 95% CI = 1.22 - 4.44), airpollution of working environment, which were filled with dusts (OR = 2.35, 95% CI = 1.18 - 4.70) and chemical fumes (OR = 5.15, 95% CI = 1.44 - 18.40) were strongly associated with pulmonary tuberculosis. BMI also had strong relationship with TB (OR = 4.72, 95% CI = 2.68 - 8.33). CONCLUSION: Poor environment and exposure to dust and chemical fume under working condition, low BMI, smoking combining alcohol consumption were the risk factors of adult pulmonary tuberculosis in Chengdu, China.

Adolescent↗